1997 F-150 4.2L 4x4 5spd 283k miles...

Pops bought the truck new. Says truck ran fine one week ago, now starts after sitting for a few hours and dies instantly. After initial start, the engine won't even attempt to fire. Engine has spark, air, and fuel-rich exhaust smell. Fuel pump is functional, and the truck WILL burn a shot of starting fluid and die instantly. All fuses are good and relays check out fine. The start/die symptom almost makes me think sensor. Pumping accel & multiple switch cycles net no different results. Possible CPS in need of replacement? Only CELs are P0430 & P0401 which the truck has had for months now. P0430 came on after gutting the cats and P0401 has been on for years. The man doesn't believe in maintenance besides oils/filters so don't jump me for the neglect fellas.

Any input on the situation? My AE hasn't been delivered yet so I can't get much more detailed than I already have as for CELs. Thanks!

 

... nothing? Fuel rail pressure is 0.

 

How did you determine the fuel pump was functional, if fuel rail pressure is 0?

Usually, this is a bad fuel pump, but could be a tripped inertia switch, a bad relay, a blown fuse, or a problem in the wiring in between.

 

I pulled the fuel pump and powered it up while it was off the truck. It isn't the inertia switch - checked it first. Fuses all check fine. and wiring SHOULDN'T be an issue as its all factory and in great shape but I won't rule it out completely. Is there a specific diagram or set of schematics I can obtain somewhere that shows what is where in the fueling system on these trucks?

 

Well I hooked a 12V power from the battery to the fuel pump and the truck runs now. What causes only getting a 5volt signal to the pump and will it hurt anything to be ran off a seperate switch full time?